Robert F. Kennedy Jr. Gets It Wrong About African-American Boys And Autism

Earlier in July, Robert F. Kennedy Jr. trumpeted what he called a "shocking piece" about autism and African-American boys, with the thesis that African-American boys have a "disproportionate risk of autism." Yesterday, I addressed another piece of his, in which he shockingly managed commit a sin of omission with every fact he urged on the reader. Either he's very, very bad at reading scientific studies or he's very, very cynical about the target audience for his latest book.

The "shocking piece" about African-American boys and autism turns out to be shocking only in the surprising fragility of the evidence that Kennedy expects to support that claim and how easily dismantled it is. He attempts to lay out an argument that African-American boys (if ethnicity is a factor, then why not girls, too?) are more susceptible to autism and that something in vaccines must be responsible. Yet a look at each source he cites to support his thesis reveals no support for it at all.

1. Claim: The US Centers for Disease Control (CDC) has data showing a connection between vaccines and autism in African-American boys.

First, Kennedy once again trots out the beleaguered "CDC whistleblower" William Thompson and Thompson's claim that unpublished data from a CDC study showed an association between vaccines and autism in African-American boys. What Kennedy omits to note is that analyses of these datadon't show that risk and that a paper alleging to confirm this association was retracted.

He says he's citing 2010 CDC data from the CDC's Autism and Developmental Monitoring Network. Looking at the data summary from that project at the CDC's website, you won't find the information he claims. What you find instead is

White children were more likely to be identified with ASD than black or Hispanic children. About 1 in 63 white children, 1 in 81 black children, and 1 in 93 Hispanic children were identified with ASD.

And this table (Table 2) shows higher prevalences of autism among white children relative to non-white children at every study site.

Also, the information doesn't include a breakdown of ethnic groups by sex, so it's unclear where Kennedy found a comparison of "African-American boys" to "white children," although comparing only boys from any group to both sexes of another group would almost invariably result in higher autism rates among the boys.

It's possible that Kennedy read another finding from the study, that

Approximately 48% of non-Hispanic black children with ASD were classified in the range of intellectual disability compared with 38% of Hispanic children and 25% of non-Hispanic white children.

and interpreted that incorrectly, although it doesn't specifically reference boys, either.

One highly probable reason that black children who are identified as autistic are more likely to also be identified as intellectually disabled is that these two features together tend to be more readily diagnosed than autism in the absence of intellectual disability. In other words, African-American children are more likely to be overlooked diagnostically unless they show very obvious signs of resource need. Many studies have shown that unless intellectual disability is also present, non-white children in need of services and interventions tend to go undiagnosed.

Kennedy's next citation is a 2014 study in Pediatrics. He offers this study as proof that African-American children are more likely to have autism. Kennedy claims that this study

showed higher rates of all categories of autism among African-Americans in Los Angeles County compared with Caucasians, with the incidence of severe autism elevated by 263 percent among foreign-born Blacks and 152 percent for U.S.-born Blacks as compared with U.S.-born whites.

The authors reported relative risk, they didn't look at foreign-born children, and they didn't look at "severe" autism--they looked at autism co-existing with intellectual disability. The children in the study were all born in the US (per the Methods: "We studied children born to mothers who resided in LA County, California, between 1995 and 2006"), and the variable was whether or not the mother was born in the US or elsewhere. The ethnic identification of the children is not reported.

What the authors really found was as follows: Autism rates in analyses without adjustments were lower for Hispanic and black children whose mothers were born in the US. When the authors adjusted for factors that also might influence autism risk, the children of US-born Hispanic and black mothers had "similar or higher" risks compared to white children in the US, which the authors say may reflect factors of socioeconomic status and diagnosis variability. They also note that "maternal life stress events" associated with immigration and dietary factors, such as folic acid and vitamin D intake, which both tend to be insufficient among non-white US mothers, might play a role in autism rates. And they point to exposure to unfamiliar infectious agents as another possible environmental influence.

Finally, the authors did not find a "152 percent" elevation of "severe" autism incidence. Among the many analyses the authors performed, the strictest one controlled for the most factors, including the regional center where the child was a client. With that analysis, they found a relative risk of 1.52--or, compared to the child of a US-born white mother, 0.52 times the risk for an African-American child of a US-born mother to be diagnosed with autism and intellectual disability. Regarding autism in general, the authors write

Risk for children of foreign-born white mothers was 4% higher compared to children with US-born white mothers. Based on these results, US-born children of black mothers had risk values (14%) that were much closer to those of US-born children of US-born white or Hispanic mothers (13%) or foreign-born white mothers (4%) than children of foreign-born black mothers (76%). The difference of 76% versus 14% for children born to black mothers suggests a factor other than ancestry at work.

What Kennedy doesn't mention is that under the strictest analysis, a white child of a foreign-born mother had a 1.2 relative risk, or 0.2 times the risk for autism with intellectual disability. And while that relative risk for black children born to foreign-born mothers under the most strict analysis was 2.63 (with data for only 13 children), it also was 2.27 and 2.45 for children whose mothers were born in the Philippines and Vietnam, respectively.

Indeed, a look at all of the data from this paper (Tables 2, 3, and 4), without cherry-picking, shows big relative risks for all measures for children whose mothers were born in Vietnam and the Philippines. These broad increases relative to ethnicity and place of birth point to sociocultural and maternal factors in autism diagnosis, as the authors discuss. I reached out to the authors regarding the accuracy of my interpretations and received confirmation of their accuracy from the senior author.

4. Claim: Black children are at significantly greater risk for "regressing into autism" following Hep B vaccination.

As the fourth and last citation to support his claims, Kennedy cites this paper (I infer; he gives no author names or links). He writes:

A 2010 study in the Journal of Toxicology and Environmental Health showed that Blacks were at significantly greater risk for regressing into autism after receiving the thimerosal-containing Hepatitis B vaccination series as infants. When analyzed further, the data showed that Black boys receiving the HepB series were 53 percent more likely to have autism than those Black boys not receiving any HepB shot.

This study didn't address "the HepB series." It used only a record of having had the first HepB vaccine in the first month of life and compared having that shot to never-vaccinated or later-vaccinated boys. The abstract of this paper, oddly enough, does not include the numbers of autistic children analyzed. That might be because there were only 33 out of almost 7673 boys (even fewer in some of the analyses) and that of these 33, only 9 children received the first dose of the vaccine in question. Three of those nine were African-American.

The paper does not cite odds ratios that match the claim of 53%, and a comparison would have been questionable given that six of the African-American boys were autistic (three who had gotten that first shot) and 927 African-American boys were not autistic, 15% (142) of whom had gotten that first shot. The analysis does not mention "regressing into autism," and 71% of those 33 autistic children did not receive the infant vaccine.